https://repositorium.sdum.uminho.pt/bitstream/1822/16850/1/pp.pdf

Extraction of antioxidant phenolic compounds from spent coffee grounds

Psidium guajava (guava) is well known tropic tree which is abundantly grown for fruit. Many countries have a long history of using guava for medicinal purposes. This plant finds applications for the treatment of diarrhea, dysentery, gastroenteritis, hypertension, diabetes, caries and pain relief and for improvement in locomotors coordination. Its leaf’s extract is being used as a medicine in cough, diarrhea, and oral ulcers and in some swollen gums wound. Its fruit is rich in vitamins A, C, iron, phosphorus and calcium and minerals. It contains high content of organic and inorganic compounds like secondary metabolites e.g. antioxidants, polyphenols, antiviral compounds, anti-inflammatory compounds. The phenolic compounds in guava help to cure cancerous cells and prevent skin aging before time. The presence of terpenes, caryophyllene oxide and p-selinene produces relaxation effects. Guava leaves contain many compounds which act as fungistatic and bacteriostatic agents. Guava has a high content of important antioxidants and has radio-protective ability. Quercetin is considered as most active antioxidant in the guava leaves and is responsible for its spasmolytic activity. Its ethyl acetate extract can stop the germ infection and thymus production. Guava possesses anti-viral, anti-inflammatory, anti-plaque and anti-mutagenic activities. Guava extract shows antinociceptive activity and is also effective in liver damage inflammation and serum production. Ethanolic extract of guava can increase the sperm quality as well as quantity and can be used for the treatment of infertile males.

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The phytochemistry and medicinal value of Psidium guajava (guava)

A novel high throughput method based on the DPPH dry reagent array for determination of antioxidant activity.

A systematic review on COVID-19 pandemic with special emphasis on curative potentials of Nigeria based medicinal plants

In this study, three types of solvent extracts from two cultivars of papaya fruit (Hongkong and Eksotika) were used to examine the effects of extraction solvent on total phenolics content (TPC), total flavonoids content (TFC) and antioxidant activity by ferric reducing antioxidant power (FRAP), 1,1-diphenyl-2-picryl hydrazyl radical scavenging (DPPH) and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) were determined spectrophotometrically Results showed that extraction solvent had significant effects on TPC, TFC, and antioxidant activity of methanol and acetone extract The highest content of TPC, TFC and antioxidant activity (FRAP, DPPH and ABTS) were found in 50% methanol and 50% acetone extracts The TPC varied for both cultivars (Hongkong and Eksotika) from 1635 to 4665, 6750 to 2338 mg gallic acid/100 g fresh weight, and TFC were between 1940 and 3617, 3981 and 2104 mg quercetin/100 g fresh weight and antioxidant activity (FRAP from 12484 to 9023, 19059 to 15998 mg Trolox equivalents/100 g fresh weight), DPPH were between 4782 and 2872%, 7456 and 3857%) and (ABTS from 5734 to 3149% and 6906 to 3484%), respectively The largest amount of TPC and TFC which leads to more effective radical scavenging effect was shown by 50% methanol extract Moreover, amount of phenolic compounds and antioxidant activities increased in methanol and acetone extract Therefore, a positive correlation occurred between antioxidant activity and phenolics compound Methanol 50% and acetone 50% solvent showed the greatest capability in extracting antioxidants and inhibiting the free radicals produced It was concluded that extraction solvent play important roles on the phenolics compounds and their antioxidant activity of papaya fruit extract

	 

	Key words: Papaya, extraction solvent, antioxidant activity, phenolic compound

https://www.academicjournals.org/article/article1386586217_Addai et al.pdf

Effect of extraction solvents on the phenolic content and antioxidant properties of two papaya cultivars

Preservatives are substances added into product to prevent their premature spoilage. Preservative helps to prolong the product’s shelf life by protecting the product from microbial growth and oxidation process. In this study, the potential of a Piper sp. as preservative for cosmetic products is being investigated. The exploration begins with the screening of major phytochemical groups; flavonoid, steroid, alkaloid, saponin and triterpene. Evaluation of biological activities exhibited the plant possessed antimicrobial property towards two strains of Staphylococcus aureus and free radical scavenging capacity. The minimum inhibitory concentration values (MIC) for both S. aureus ATCC 25923 and S. aureus ATCC 6538 is 2500 mg/mL and 312.5 mg/mL respectively. Free radical scavenging capacity of the plant was determined via Superoxide scavenging assay and DPPH radical scavenging assay and the capacity values are 76.4 + 0.35% and 59.7 + 0.75% respectively. Cytotoxicity study was also carried out to determine the safety of Piper sp. where median inhibitory concentration (IC 50 ) value for normal kidney cell lines (Vero) is 62.96 mg/mL and normal liver cell lines (WRL-68) is 69.91mg/mL. The extract of Piper sp. was formulated as cosmetic preservative ingredient especially for topical product. The specification of ingredient’s characteristic and performance were described based on colour, odour, pH value as well the solubility in product formulation and stability at 4°C, room temperature and 40°C.

Vimala Subramaniam

Papers

EVALUATION BIOLOGICAL ACTIVITIES OF Piper Sp INTENDED FOR SKIN FORMULATION PRESERVATIVE